The specific aim of the proposed research is to develop a noninvasive method to reliably construct, by means of computer, three-dimensional images of the left ventricle and mitral valve utilizing multiple planar views obtained by real time two-dimensional echo-cardiography. Various parameters of left ventricular function such as volume, ejection fraction and mass will then be calculated from the three-dimensional reconstruction. To reduce or eliminate errors in some of the recent preliminary attempts at three-dimensional reconstruction, the transducer will be mounted on a mechanical arm which permits only one degree of freedom which is rotation about its axis. The transducer will then be applied to the patient's chest wall in the region of the cardiac apex, the apical four-chamber plane will be imaged and then the transducer will be rotated in 5 degree increments from 0 to 180 degrees to obtain various planes passing through the apex. The planar two-dimensional echocardiograms will undergo image processing, endocardial edge enhancement as well as digitization. Angular reconstruction of areas will then be obtained at different axial locations and three-dimensional reconstruction performed. The apical rotation method proposed by us has not been previously reported, is not based on any goemetric assumption of left ventricular shape and is relatively uncomplicated. The method will first be validated utilizing tissue specimens and in vivo dog studies and then will be applied to human subjects. Our method will be expected to be more reliable than other three dimensional techniques. Two techniques for presentation of three-dimensional images will also be examined to identify a method which will provide best display and cost effectiveness. The effective digital representation of the time varying data of the left ventricle and the mitral valve will also enable us to use a suitable body fitted coordinate system for the investigation of blood flow patterns in the left ventricle without recourse to Doppler echocardiography. Simulated real time flow characteristics of the left ventricle will be attempted and if successful will have far reaching clinical implications; for example, left ventricular wall stress and strain patterns can be determined and local pressure-flow relations may predict impending left ventricular aneurysm formation or impending myocardial wall rupture.